Technical Field
The present disclosure relates to a photographing optical lens assembly, an image capturing unit and an electronic device, more particularly to a photographing optical lens assembly and an image capturing unit applicable to an electronic device.
Description of Related Art
In recent years, with the popularity of electronic devices having camera functionalities, the demand of miniaturized optical systems has been increasing. The sensor of a conventional optical system is typically a CCD (Charge-Coupled Device) or a CMOS (Complementary Metal-Oxide-Semiconductor) sensor. As the advanced semiconductor manufacturing technologies have allowed the pixel size of sensors to be reduced and compact optical systems have gradually evolved toward the field of higher megapixels, there is an increasing demand for compact optical systems featuring better image quality.
A conventional optical system employed in a portable electronic product mainly adopts a lens structure with fewer lens elements, such as four or five lens elements. Due to the popularity of electronic devices with high-end specifications, such as smart phones and wearable apparatus, the requirements for high resolution and image quality of present compact optical systems increase significantly. However, the conventional optical systems cannot satisfy these requirements of the compact optical systems.
Other conventional compact optical systems with six-element lens structure are developed. However, the curvatures and the refractive powers of the lens elements are improperly arranged. Thus, it is difficult to reduce the back focal length of the optical systems whereby it is hard to keep the optical systems compact. Furthermore, the refractive power of the lens elements adjacent to the object side is unbalanced so that the aberration is severe and the illumination is insufficient in the peripheral region of the image.